When should you choose a battery electric vehicle over a plug-in hybrid?

We are encouraging questions from readers about electric vehicles, and charging, and whatever else you want to learn. So please send them through and we will get our experts to respond, and invite other people to contribute through the comments section.

Here’s the latest:

My boss wants to upgrade his car to electric but is planning on PHEV (plug-in hybrid not BEV (battery electric vehicle). What are the variables a driver needs to consider to make them feel comfortable that a BEV is better than a PHEV for their needs?

Regards
Olivia

Hi Olivia – the choice between PHEV and BEV is an interesting one.

Within a limited set of parameters, a PHEV can be the best choice. If you stray outside the parameters of that usage case though, a PHEV can rapidly end up becoming a worse choice over a simple ICE car. (ICE refers to Internal Combustion Engine, which is one that runs on fuels such as petrol, diesel or LPG).

So, what are those parameters?

1. A significant majority of your regular driving trips are within the ‘EV only’ range of the PHEV (see table 1 for a selection of PHEVs and their range estimates). Generally 15 – 70km, depending on PHEV chosen.
2. You ensure the PHEV is always charged enough before those trips to ensure doing the trip in ‘EV-only’ mode. (PHEVs have relatively small batteries, so keeping them charged is often a daily, or even individual trip based, occurrence).
3. You need the extra range offered by the ICE motor over the battery-only one on a reasonably regular basis. (If only once or twice a year – it may be cheaper to simply rent a suitable ICE car or SUV for the trip);
4. The PHEV that meets your range needs is of the type that meets your other vehicle needs (if you need a small car for inner city runs, but a medium to large wagon for weekends away – the PHEV may be unpleasantly large to drive around town!);
5. You:

• • cannot afford the currently higher cost of a long-range BEV over a PHEV and/or
  • there are currently no existing (or soon-to-be-built) DC fast-charger stations on your normal long-run routes outside the return range of a BEV and/or
  • cannot justify owning two separate vehicles. (For example, a cheaper, second-hand shorter range BEV for local usage and a fuel-efficient ICE for longer trips).

Within that scenario, a PHEV stacks up well – and I know several Mitsubishi Outlander PHEV and Holden Volt owners that have extraordinarily low overall petrol usage figures due to their carefully maximising their EV-only usage over petrol consumption. (Including recharging during coffee breaks on long trips).

By the way, the Holden Volt has around 80km of EV-only range – however the Volt is only available second-hand in Australia as they have not been sold new here since around 2014.

On the flip side, if you go outside that set of usage parameters the benefits of a PHEV over ICE rapidly diminish.

For instance: if a PHEV is consistently driven well beyond its EV-only range without recharging (or driven without ever recharging, thereby effectively using it as a hybrid), the fuel savings can drop down to the hybrid level of a 5 – 20% fuel saving.

(By the way, that 20% is if you do only local stop-start traffic, and the 5% is during long-distance highway driving). If the PHEV is a larger SUV, this could be worse fuel economy that simply owning a medium sized, fuel efficient ICE car for the type of driving you are doing!

A second downside of owning a PHEV is they contain TWO drive trains, not one. (Meaning one electric and one ICE). This means they need two sets of servicing costs, and you are still stuck with the environmental downsides of creating used oil, oil filters, air filters, spark plugs and the like for disposal.

An interesting side note to the PHEV or BEV debate is that in more mature EV markets (California and Norway as examples) new PHEV sales are starting to fall as a percentage of overall plug-in car sales.

It seems people have decided that PHEVs were an interim technology. Now BEVs have gained in range and charging speed, started to fall in price AND the DC fast-charge networks are rolling out at ever increasing rates, the ownership case for owning a PHEV (as outlined above) is narrowing ever further.

In fact GM in America ended all its PHEV models early this year in order to focus only on full BEV production into the future.

Summing up: PHEVs are an excellent fuel and emissions reduction choice when looking at a single car ownership scenario, but only within a limited set of usage parameters. You therefore need to thoroughly analyse your vehicle needs before opting for a PHEV over either a fuel-efficient ICE or full BEV.